Wired and space radio reception system



March 26, 1935. R. c. CURTIS 1,995,418

WIRED AND SPACE ,RADIO RECEPTION SYSTEM Fi led Dec. 2, 1932 2 sh ets-sheet 1 l l i 'l SPACE RADIO Z0 RECEIVER INVENTOR Richard [1. [Zuriis R. c CURTIS 1,995,418

WIRED AND SPACE RADIO RECEPTION SYSTEM Filed Dec. 2, 1932 PORTION OF WIRED RADIO RANGE FREQUENCY E :1 E &

PORTION 0 BROADCAST RANGE FREQUENCY I INVENTOR Richard E. Curtis Patented Mar. 26, 1935 ii H V r r BWIREDAND-S ACE memo REoEPmIoN v SYSTEM;

Richard i i s'fisast 'oranigefn J. I I 'to Wired Radia ing, e y N Y Doration'of .1)ela g I hl licationDecemberxZ;-l zk fi N we 5301 v .isfolai i s-jf(CL-179;

' My invention pertains in general to rad'idjre ited by fcarr-ierfrequencieslto whichthe-receiving ceiving systemsand specifically relates-to asuch :organizati'onis' norrmarlly;unresponsive. vTo acsystemsfor the-selective-receptionof either wired complish this I-provide;witl iinithe unitaryyeonradio'or space radio programs. 'vertor, a -localgenerator of carrierfirequeneyos V In wired radio -broadcasting, "in which 'carrier cillations-ofa frequencyssuitable for the e'xisting 5 signals are transmitted over 'commerciahpower -receiving;organization; snowever; this frequency distribution networks, the carrier frequenciesemmay-:be adjusted to the :a-desired value; Wired 'ployedgare' usually within a range of 25 to .100 ra'di'o program-s,- lwhich are[transmitted-over a kilocycles. On the other hand, the' transmis ,gpower network at a plurality-of discretecarri'er 3 10 sion frequency range employed 'spaceradio ifrequ encies' are -utilized to=modulatefthe loeally' -10 broadcasting beginsataround SOO-kilocyclesL'E It. generated carrierfifreguenoy; !1"he 'loca1ly gen'- isquite-evident, therefore, that there Zis-consid-- erated frequency then gappears:as a 'carrier with erable difference in the frequency ranges {em a plurality ofdipper and iowerside bands,-ther e ployed-in wired radio broadcasting and space being an upper 'and lower s-i'de band forr each of I radio broadcasting. It follows that apparatus thewired radio:program'channels." In a'ccord- 1-5 especially designed for the reception of space =ance withthe method of' my'invention,' the selecradio signals'isunsuitedfor'the eificient re'cepti'on circuits" in-either ther-'eonvertomor the-exg ton: of wired radio signals, and vice versa'; -My isting receiviiig organization;-aretuned to one invention'contemplates' providing a-system'whereof the sidefbandswliereby the wiredfradio pro- I by a; normal space-radio receiver can-beconv'engram; is reprmiuce'd'oveflthe existing *radio ree- 2'.) iently adapted for useinthe emcientreception-of ceiving organizationl wired radio signals infrequencyranges-"towhich Referringtofithefirawings in detail -theeonspace radio receivers are' not normally responsive. vertor -1" is=provided with a eam'e s havmga-serw One of this objeets'of'myinvention consists'in ice plug forconnection withany-crdinaryserve. it

' providinga convertorior use in conjunction-with ice outlet of-the vcons'urners power "distribution 25 an-existingiradio receiving system 'for rendering system forming; part 0 the commercialpower the same-operativefor the? eificientj-reception' of distribution network. wired' radio programsare programs transmitted'within frequency ranges broadcast over-this"power distributionnetwork, to which'the receiver is normally unresponsive. schematicallyindicated-by the power 1ine's 4 in Another object consists in" producing a 'sy'stem Fig. 1. The-wiredradio 'proigrams'consist'fof sev- 3 V for program receptionin ,whicha plurality of diseral difierent program modulation chann each crete program carriers areu'tili'zed to simultanehaving diiTerentcar'rierfrequencies; rela ously modulate a locally-generated carrier from 'tionshipof-thesefrequenciesalong theifreqi-rency I a which the desired program isselected-by tuning. spectrum-is ihdicated in-"Fig. Beferring' to These and other objects will .be apparent from 3. curves-AfffBand --C ---ccrrespond to 35 the following, reference being had to the accomthree-different programs'of't-he-wired radio chanpanying drawings'in w hich: g I e nels, althoughftheremaybe othen-channelsfif 1 is a diagrammatic representation of one desired Each o'f the {modulation "frequen cies; embodiment-of the system of my invention; 'within' anyone ofjthese channels -is impressed 40 Fig. 2. illustratesa typicalrinsta11ationof--the upona part-iculancarrierfrequency. Means'are 4 system of my invention showing a unitary conprovided, accordingto'sys'tems well-knowniri the vertor mounted upon an existing space radio reart,*fo'r-transmitting-butfonesideband ofymoidnceiver for rendering the same responsive to wiredlation"irequenciesJfFor -examplajthe-curvqfA?) radio programs; i extends- -*frorn'*frequenoyqfar"to :faz. "The-carrier "Fig.13is'a graphical representation""of variousl frequency issubstantially fe;,fthemodul ti xe 45 frequencies employed in wired 'radio' broadcasttending' in' the '--upper-sideband"represented by Vin-grand r 7 those rrequencies; {falling- "within the ;range -Fig.i4 is'a graphical representation of frequenfez- 731; -'Similar conditions prevailjfor channels cies employed-in accordance with the principles B and ffC; itbeingapparent thatth three carofmyinvention. f r u h 7 -In carrying out my invention Iprovide auniand'fci; area eparatdfromf-eachother-"spin taryconvertor which can be conveniently} placed ciently i to' =a-vo1 marine-nee within the-wired upon or associated with-anexistingradio'receiv-' radio range; I 1 'l'. ingorganizationwherebythe'iatten'may-beren '"*Referiing back to'PFig.1;"the cable5cerrveys dere'd responsive to-signa1sor programs transmitboth cornmercial powen. such'as oocycle -alter- 55 rierf 'frequencies-whieh are substantially iii, ffbi,

vertor. Connections are provided from the ca-,-

nating current, and. the several wired radio carrier frequency program channels to the conble to a filter 13. The filterl'3 is provided with condensersfwhich permit the carrier frequencies to pass therethrough but which prevent thepassage ofg the low frequency commercial alternating current. The filter 1 3= is-of the. band pass type broadly responsive" to the several wired radio program channels and a responsive curve substantially in accordance with-curve D in Fig. 3 having ilowcrjandupr' with an oscillator 15. Oscillator includesan electron tube 16 and a tunable oscillationcircuit wired radio frequency channels: Space radio receiver 2.is indicat iveof an. ex -isting radio receiving; organization normally ,;unresponsive. to the wired radio.;:frequenciesThe radio receiver 2: comprises; means well; known, in the art .for the reception; of space radio signals and includes a tunablecircuit: including .the a'd.

29} controls the f. potent including the adjustable condenser 17 .for v-producing' controlled high frequency oscillations;

The' oscillation circuit; including; the adjustable condenser 11 is broadly-responsive. tothe several justable condenser 20. andalso electronltubes-as -we asa oud sp aker .1-

. he' p we u p y forth electrontubes within the'receiver 2 ,is derivedfrom a: cable-6 usually foundw th such e v r ln..t e. perati f the space; -ra dio receiver ;2,v however, in accordance. with -;.the pr n ip es of i ve t on, the ca le. 6 h v n a. service 1P11 ;:th 3 0n, .is connected within; a service; outlet for; attachment -p ov de l.with n e' mv tor ss wn in E a. c n e t n. is m i ste d; o .directly to the consumers power servioe loutlet .as u is usually the case. Such an arrangement or. q pectipathe p w p siprov de i 12 Q tid8d i 5. e pow rs pp y ui in h nv. t9r -..T d ct m ed c .1 ey ptsl th sq nt en an mod lat on of: rier freq ienr energ by the mm r i l .-.p w r c nsumin e m nts f-.. i h the q ve o 1 1' the receiver 2.? ,The power p circuit within the sem ster i de he'n im wind n of la ransi m r. ma p werr a' k 1 .A s t h sqezza n q s t e; PQWBIZ c r u t f m c bl nd. h o imp d n 2.1 il-bo he an e rm r 1.2 andt spa er d cs ceive Th P w r a k 1 in lu e a rect e tube; and su a le .filter nemea is mm h th rectified 1 n -.S 1P 1 -;w i i d r tQz s a e s a e u e- .16. .at... .itab e o rat lt gesfl'henutnut circu t l t in d a potentiometer 24 and; inductance 2 5, f lfhe ind c ane li eu le iw hjam n t nce 26 w h. ss na st with wi ius a l co d se 27 to form a trapi circuit,-the use of-whioh will be more apparent hereinaften The condensers 1'7 and27 arelmechanically coupled'together so that. the control thereof. nay be exercisedfroxn a singlelknob28fas shown 1n;,Fig :2 Y The knob h uPu iiit in. t eo l at -t a mss'i e ne s i me e -.imh des s e na.- tioil w a wn ac a ted.t9 -be.. ;bx "a 7 switch blade 32. The same-circuit also includes q t qn to th r-con ct ad pted. iaab n d .by. t Switch bla e; .1-1. aaiante 1,995,418 8, whichmight ordinarily be used with the radio 2 '7 to thespace radio receiver 2.

31 connects the antenna 8 to ground. In this 'coiiditionlthe space radio receiver 2 is in a receiver 2, is connected to the convertor l and extends to a pair of contacts one ofjwhich is terconnected and controlledlb'y knob. 3,0 on the.

convertor. (See Fig. 2) In the position shown in Fig. l, the switch blade 22 connects the transformer 12 of power pack 11 to the power lines .4-. through"cable 5;. Switch blade 32 connects the output of the oscillator 15 through a wire Switch blade condition for reception of selected programs in the wiredradio irequency range. The operation of the system'of my invention for such recepti'on"'wi1l' now be described:

. It is,f.of course, to be understood that-the frequencies inthe wired radio-jrange, such as represented in Fig. 3, are of a low..order,;while, the

frequencies to whichthe'receiver 2 are normally responsive are 'ofa much'higher order. -For example,- the frequencies depicted in Fig. -3- may all be within a range below kilocycles while the range to which receiver 2 is responsive may begin Eat-around 50o kilocycles; H v

theioperation of my system, theentirWired gradio-range which mayinclude any numberyof discrete. program modulated; carrier frequency channels, is passed through filtenliipand made to-rnodulate the sustained high frequency oscillations produced by oscillator 16,- The frequency of the oscillator. 16 is sufficiently highJ'So-that .the attendant. modulation frequencies will fall within the range .to which the. receivenZ isnormallyresponsive. wThis frequency may .be inthe neighborhood.- ofv 6Q0ekilocycles or more, This carrierproducepl byqeleotron tube 16 .;is represented in Fig.4 asthe line .C. The carrier frequency] channels Willgnow appear as; upper and lower side bands as shown in Fig. 4;. The channels A 13, and C willghave upper sideqbands as represented by the curves A337, and C'., While the sameichannels will have lower. side bands represented by the curves A,',B.',- and C, For example; theffrequency range or-the upper side band of curvei fif is the range V (0+fa2) (Q-l-fa1)? while, on the other hand, the rangerepresented by'the lower side band A' is;

Corresponding conditions ,prevail; for the. other side bands shown in f 'igr i The frequency .range immediately adjacent the carrier :0 and causes. in s the. operation of my system, the

cirouit26.27: is tuned to t he frequency ran'geof extraneous modulation represented by thecurve 'Xin Fig. 4andservesas atrap. circuit for rejecting the. energy-withinthis frequency range.

The frequency range including the. upper and lower side bands are directed throughtheoircuit inoludingyswit'ch blade 32 to' the space radio re iY 12i-; Th? f .Q reception: cuitlinclucling the c'ondenser20, are proportioned 1 v Substan iall od h n s charact r'- istic having comparative frequency bandwidth such as represented by the curve E in Fig. 4; The Width of the curve E is of the same order as any one of the. side band curves. It will be'u'nder stood that the frequency range between the side bands, such as by the side band A', and side band B, is actually'greater than the width of the curve E although the drawings are in condensed form for simplicity of representation; Adjus'tinent of condenser 20 in the space radio receiver 2 serves to shift the range represented by curve E along the frequency spectrum so that the receiver 2 is responsive to any selected one of the side bands A, B, C, A5, B", or C". However, according to the method of my invention, the curve E may be maintained stationary with respect to the frequency range, that is, the condenser 20 may not be adjusted, while adjustment of condenser17 serves to shift the carrier 0, together with its modulation side bands, along the frequency spectrum with respect to the curve E so that a desired one of either the upper or lower side bands falls within the range of the curve E.

It will be seen therefore that single side band re-.

ception, with its attendant advantages, is provided by this system.

The chief advantages to be derived from my inventionjreside in that a simple and compact arrangement is provided for adapting an'existing radio receiving organization for the reception of frequency within ranges to which it is normally unresponsive. A further advantage consists in that tuning is accomplished by simple "means and that-hum and extraneous modulation are considerably reduced by the various arrangements inherent in the system of my invention. I

'When it is desired to operate the receiver 2 solely as a space radio receiver, the switch bands .22, 32,- and 31 may be moved by knob 30 so that:

the power circuit to the power pack 11 is interrupted, the output circuit from oscillator 15 is grounded by switch blade 31, and switch blade 32 connects the space radio receiver 2 to the anfromthe intended scope of'my invention. I do not therefore desire to limit-myself to the foregoing except as may be pointed out in'the appended claims. r

What I claim as new and original and desire to secure by Letters Patent of the United States is: 1. In a systemfor thereception of programs comprising, a filter circuitfor the simultaneous reception of a plurality of programs each'con-.

sisting of a carrier frequency and modulation frequencies, means for locally producing a high frequency carrier modulated by said programs to produce a plurality of side bands corresponding to said programs but removed in the frequency spec'- trum from the vicinity of therange of extraneous or noise modulation, and a selection circuit having parameters designed for the reception of frequencies within a range substantially the extent of one of said side bands, and-a rejection circuit responsive to the range of extraneous modulation frequencies, the method of selecting a desired program including, simultaneously shifting said high frequency carrier and the frequency response of said rejection circuit along the frequency spectrum maintaining the same relationship therebetween whereby said side bands of said high frequency carrier are shifted along the frequency spectrum so that one of saidside bands falls within the range to which said reception circuit. is responsive and said rejection circuit continuously f rejects said extraneous modulation frequencies.

2. Aradio receptionsystemcomprising, a filter circuit for the simultaneous reception of agplu- 1 rality of program channels each comprising a carrier frequency and modulation frequencies, means connecting said :filter circuit :to commer.- cial power lines for-deriving said program frequencies therefrom an oscillator coupled to said filter and including an oscillation circuit broadly responsive to said program channels whereby a high frequency carrier is produced having modulation side bands corresponding to said program channels, a space radio reception circuit coupled to said oscillator and responsive to frequencies within a range substantially equal to one of said side bands, and means for relatively shifting said high frequency carrier and the response of said space radio reception circuit along the frequency spectrumwhereby a selected one of said side comprising, a unitary housing, a filter within said housing and designed to simultaneously receive a plurality of program channels each comprisingcarrier and modulation frequencies, a space dis charge tube and oscillation circuit for producing a high frequency carrier within the range to which said space radio receiver is responsive said oscillation circuit being broadly responsive to all of said program channels, a power pack within said convertorand including a transformer and rectifier device, a cable having an;

attachment for insertion in a-consumers power outlet for supplying both commercial power to said transformer and carrier frequencyenergy to said filter,.said power, pack serving tosupply operatingvoltages to said space discharge tube, an attachment in said convertor for connection with a power supply cable ofsaid receiver, a

switchfor controlling a circuit from said first mentioned cable to said attachment and to said transformer, an inductive impedance in said convertor for-restricting the passage of carrier frequency energy from said first mentioned cable to;

said transformer and'to said attachment, a circuit within said convertor for connection with an necting said radio receiver withsaid antenna circuit or with said potentiometerantenna, a potentiometer coupled with the output V of said oscillation circuit, anda switch for con-1 2 4. A convertor in accordance with claim 3 in eluding an adjustable condenser in said oscillation circuit, and a rejection circuit includingan adjustable condenser responsive to extraneous or modulation frequencies, common mechanical means for actuating said condensers, and com-" mon mechanical means for actuating said switches. e

5. A convertor for adapting a radioreceiving organization for thereception of programs with in ranges at whichitis not normally responsive comprising, a unitary'housing,frequency chang 7 ing means within said housing including circuits and'electron discharge tube means, jacable conne'ctedwith said unitary housing and having an attachment for insertion ina-consumerspower outlet for, supplying carrier frequency program energy to said frequency changing means, as well as commercial power for'operating said discharge 'of commercialpowerfor operatingsaid spacedischargtube means, .an output connection" for said convertor for. delivering said carrier virequencies to said radio receiver at a converted fre quen'cy, an antenna circuit, and means carried by said convertor for operably, connecting said radio receiver with said antenna circuit orwith said output connection for reproduction of programs.

I 6. yA convertor in accordance with claimv5 carrying an -"attachment: for connection'with the power supplycable ofsaid receiver and including azcircuit to said convertornpower supply cable, said circuitincluding-an impedance for restrictmg the passageof carrier frequency. energy'from :1 said power supply cable to'said attachment forvpreventingtransfer of carrier frequency energy betweenfsaid convertor power. supply cable and said radioreceiver; ro v r RICHARD C. CURTIS.- 1o 

